The present invention generally relates to toggle anchors for securing hardware to walls, and specifically to toggle anchors that have threaded anchor members and a lockable self drilling swivel toggle member.
Securing hardware to walls that have hollow spaces presents a particularly difficult problem to solve. Typically, a nail or screw will not hold fast in plaster, gypsum, thin plywood, metal siding or other such materials that are not backed up by a solid reinforcing member such as a stud, joist, or the like. The traditional prior art approach to this problem has resulted in the well-known toggle anchor or toggle bolt. The standard toggle anchor typically consists of numerous parts including a body portion having a retainer bar pivotally attached to its inner end, usually articulated and pivotable about a hinge, and kept in an open axial position by a spring bias. In addition, a nut and bolt combination is provided as a central axis about which the hinged toggle portion suspends. In use, a hole is first drilled through the wall to which the anchor is to be secured. The anchor is then folded up (against its spring bias and about its hinge), positioned into the hole, and moved inward until the retaining bar is through the wall and disposed in the open space behind the wall so that the anchor then springs open and pivots into a securing position. An example of this type of toggle bolt is described in U.S. Pat. No. 5,702,218, which is hereby incorporated by reference in its entirety.
Another prior art toggle anchor is disclosed in U.S. Pat. No. 5,716,179, which is hereby incorporated by reference. The toggle anchor described in U.S. Pat. No. 5,716,179 includes an elongated cylindrical tube having a channel and a spring loaded threaded ball for receiving a bolt. Once the tube is placed through the wall the spring acts to rotate the tube parallel to the blind side surface of the wall. However, the device is not self drilling and a hole must first be drilled before the toggle anchor is placed in the wall.
The above-mentioned traditional types of anchors have been replaced by self drilling single unit toggle anchors that include an anchor member and a swiveling toggle member mounted to the anchor member allowing the toggle member to slide and pivot. Toggle anchors of this type have a reduced number of mechanical parts and are thus easier to manufacture and use in general. The toggle member is securable in a parallel position relative to the anchor member and has a self drilling distal end. When the unit is placed upon the room side surface of a sheet rock wall and a torque is applied, the self drilling distal end burrows through the sheet rock and creates a hole just large enough for the toggle anchor to slide through. The anchor member is formed with a threaded head portion that is larger in diameter than the toggle portion and hence larger than the hole drilled in the wall. As a result when the threaded head portion of the anchor member engages the surface of the wall and a torque is again applied, the threads of the threaded portion burrow into the surface of the wall outside the circumference of the previously drilled hole. The anchor member is formed with a counter sunk flat head that seats the anchor member in the wall securely and prevents complete burrowing of the anchor member.
When the anchor member is securely seated in the wall a self tapping screw is driven through a bore in the center of the anchor member. As the screw advances through the bore the leading edge of the screw engages the toggle member and displaces it from its secured position relative to the anchor portion. Typically, toggle members are counter balanced and once displaced from the anchor member a weighted end of the toggle member will pivot, under the influence of gravity, to a position parallel with the blind side of the wall and orthogonal to the anchor. The toggle member is formed with a bore that becomes co-linear with the screw when the toggle member is parallel with the blind side of the wall. As the screw continues to advance the leading edge enters the bore of the toggle member and the toggle member then is transposed towards the blind side of the Wall along the length of the screw to a position abutting the blind side of the wall and securing the toggle anchor thereto.
Self drilling toggle anchors of the single unit type suffer from several disadvantages. It is important to evenly distribute the torque applied to the anchor member, via a screwdriver, throughout the toggle anchor in order to efficiently burrow through a wall. Because the toggle member of the above described anchor has two degrees of motion relative to the anchor member, i.e., it slides and pivots or swivels relative to the anchor member, a torque applied to the anchor member tends to be distributed unevenly throughout the toggle anchor. This can create undesirable shear forces between contact points of the anchor member and the toggle member which can cause the toggle anchor to burrow offline from the intended target area, misalign the seating of the toggle anchor, and possibly separate the toggle member from the anchor member. A typical solution to the shear force problem is to manufacture the toggle anchors from stronger materials such as metal. However, in order to keep the manufacturing simple and inexpensive it is desirable to forgo the use of metal for plastics and still maintain high structural integrity within the toggle anchor.
It is therefore an object of the present invention to provide a toggle that distributes a torque load evenly across the entire toggle anchor. It is also an object of the present invention to provide a toggle anchor that can be manufactured inexpensively while maintaining high structural integrity. It is an additional object of the present invention to provide such a toggle anchor made substantially or entirely of plastic.
Another object of the present invention is to provide a toggle design that significantly reduces the endwise profile so that a smaller hole can be drilled relative to the diameter of the anchor member. Still another object of the invention is to reduce the number of mechanical parts needed to fabricate a toggle anchor. Again, an object of this invention is to provide such a toggle anchor made essentially or entirely of plastic.
These and other objects of the invention are met by providing a toggle anchor for securely anchoring hardware to the surface of a wall, featuring an anchor member having a bore and a channel and a self drilling toggle member slidably disposed within the channel and aligned with the axis of the bore. The toggle member is lockable in a first position to facilitate distributing a torque applied to the anchor member to a cutting member drilling or burrowing through a sheet rock wall until the anchor member is securely seated within the wall. The toggle member is displaced in a direction parallel to the longitudinal axis of the anchor member and then pivoted to a second position orthogonal thereto. The toggle member is formed with a bore that becomes co-linear with the longitudinal axis of the anchor member when the toggle member is positioned in orthogonal relation thereto. As a screw advances through the bore of the anchor member, a leading edge thereof engages the bore of the toggle member and transposes the toggle member along the length of the screw until the toggle member abuts and is secured against the blind side surface of the wall. These and other objects, features, and advantages will be more completely set forth in the following sections.
In brief, then, the present invention is a self drilling toggle anchor comprising an anchor member featuring a head portion, a locking portion, and a central portion defining and bordering a channel disposed between the head portion and locking portion, for securely anchoring hardware to a wall with a hollow portion. The head portion of the anchor member features external threads and a counter sunk flat head support lip. The toggle anchor also comprises a toggle member having a body disposed within the channel of the anchor member and a drilling portion for drilling through the wall with a hollow portion. The body of the toggle member is slidably mounted to the anchor member within the channel allowing the toggle member to be movable from a first locked and fixed position parallel to a longitudinal axis of the channel to a second position orthogonal to the longitudinal axis of the channel. The body also includes upper and lower pairs of shoulders that support and contain the body within the channel.
The toggle member is releasably lockable in the first position to the anchor member to provide even distribution of a torque applied to the anchor member along the length of the device. The locking portion of the anchor member features a rim recessed from the distal end of the anchor member and support projections extending from the distal end of the anchor member. The rim and the support projections define and border a locking groove which receives and locks the toggle member in the first position. The toggle member is provided with a fitting portion that is adapted to frictionally engage the locking groove and secure the toggle member in linear engagement with the anchor member. The toggle member is also provided with tracks that receive ribs located on the inner surface of central portions of the anchor member and protrude into the channel. As torque is applied to the head portion of the anchor member, via a screwdriver, the torque is evenly distributed to the working end of the device, i.e., the self drilling end which is provided with a plurality of drilling blades or any conventional device for efficient drilling. In essence, a combination of the interaction of the upper and lower pairs of shoulders supporting and containing the body, the locking portion of the anchor member and the fitting portion of the toggle member, and the ribs of the anchor member and the tracks of the toggle member ensures that the torque is distributed evenly throughout the toggle anchor while drilling through a sheet rock wall having a hollow chamber.
As used herein, reference to a wall or a sheetrock wall is understood to be a wall having a frame with defined spaces between actual sheets of material covering the frame, whether they be sheetrock or paneling. The frame may be formed from any suitable material such as wood or aluminum.
After the drilling blades burrow completely through the sheet rock wall, the head portion, having external threads and a counter sunk flat head support lip thereon, becomes anchored in the room side surface of the wall. The head portion is formed with a bore through which a screw or bolt is passed in order to provide a strong cantilever for supporting hardware. The toggle anchor is designed to be used with a threaded bolt or screw. As the screw is passed through the bore of the anchor its leading edge engages, displaces, and transposes the toggle anchor from the anchor member from the first locked position to a second position orthogonal relative to the anchor member. The toggle member is formed with a bore that becomes co-linear with the longitudinal axis of the anchor member when the toggle member is positioned in orthogonal relation thereto. As a screw advances through the bore of the anchor member, the leading edge engages the bore of the toggle member and transposes the toggle member along the length of the screw until the toggle member abuts and is secured against the surface of blind side of the wall.
A more complete understanding of the features and advantages of the present invention will be realized when taken in conjunction with the following description of the drawings, description of the specific embodiments and the appended claims.